The following data are annualized returns on a group of 15 stocks 12.5, 13, 14.8, 11, 16.7, 9, 8.3, -1.2, 3.9, 15.5, 16.2, 18, 11.6, 10, 9.5. Required: a. Find the median b. Find the first and third quartiles c. Find the 55th and 85th percentiles Required: What is the probability that the device will detect at least one of two shoppers entering together